The rep said, "I can confirm that Hugh Grant is the delighted father of a baby girl. He and the mother had a fleeting affair and while this was not planned, Hugh could not be happier or more supportive. He and the mother have discussed everything and are on very friendly terms."

The identity of the baby's mom has not yet been revealed. Back in April, Grant was romantically linked to Chinese actress Tinglan Hong.

"He's going to be a great dad!" the source tells Us. "He's beaming about his daughter. He's not with the mum anymore but he's absolutely thrilled."

In 2007, Grant told Vogue he was ready to be a father. "As much as I adore myself, I'm quite keen to find someone else to care about more," he said. "I remember reading a Warren Beatty quote when he finally had children and said what a relief it was to not be all me, me, me."